Bullets Do Not Expand

by
posted on March 13, 2013
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
lessons_ah2015_fs.jpg (2)

We gunners like to think of ourselves as very precise and accurate, especially when we talk of guns and such. Much froth and furor are put forth when we hear someone say “assault weapon” instead of “semi-auto rifle,” or “clip” when they mean “magazine,” or “bullet” when referring to a “cartridge.” The misidentifying examples are almost endless. But we are guilty of at least one mischaracterization as well. And that is the so-called “expanding bullet.”

Bullets do not expand upon impact. They deform—or more accurately rivet—when they encounter a resistance at terminal velocity. Balloons expand when air is blown into them. Wound cavities expand when bullets transfer their kinetic energy into a target. But bullets do not expand. Occasionally the word “mushroom” is applied to a riveting bullet. This, too, is misleading, since “mushrooming” describes more of an eruption rather than riveting.

During the muzzleloading era guns fired lead spheres known commonly as a ball. Throughout the literature of the day the lead spheres shot from rifles, pistols and canons were referred to as balls. Our term bullet is derived from the French word boulette—meaning “canon ball” or “small ball,” circa 1550 A.D. These largely pure-lead round balls often flatten to one degree or another on impact. Seldom is this phenomenon referred to as “expanding” or “mushrooming.”

I rather doubt that my little blog is going to change the lexicon of the day, especially since I have referred to bullets expanding thousands of times during my writing career. But in the interest of accuracy, we should realize that current terminology does not properly describe the observable fact of a bullet deforming upon impact.

Latest

Remington Rimfire Ammo Roundup Lead
Remington Rimfire Ammo Roundup Lead

Remington Rimfire Ammo Roundup

Big Green feeds the .22s oh so well.

New for 2025: Kings Camo XKG Shift Collection

Kings Camo has introduced the XKG Shift Collection, a line of quiet, windproof and ultra-versatile apparel designed with whitetail hunters in mind.

Tips & Tricks for Early Season Canada Geese

As anticipated, the first family flock of Canada geese lifted off their nearby river roost, nearly skimmed the big-leafed cottonwoods and set their wings. I called once, letting the half-dozen full-body decoys do the rest. Five birds came in, three left.

First Look: Maven RFZ.1 Zoom Rangefinder

Maven Outdoor Equipment Company, a Wyoming-based brand, has expanded its premium RF series with the launch of the RFZ.1, a laser rangefinder featuring variable magnification.

Elk: A Dream Season

One family of hunters had the perfect September last year. Read on for an all-American story crafted in the mountains.

Waterfowler Bird Flu Precautions

A Michigan Department of Natural Resources (DNR) reminder, applicable nationwide, includes tips on how waterfowl hunters can protect themselves and domestic animals amid ongoing cases of highly pathogenic avian influenza (HPAI).

Interests



Get the best of American Hunter delivered to your inbox.